1. Field of the Invention
The present invention relates to substrate processing apparatuses for applying processing to substrates.
2. Description of the Background Art
A substrate processing apparatus is used to apply a variety of processing to substrates such as semiconductor substrates, substrates for use in liquid crystal displays, plasma displays, optical disks, magnetic disks, magneto-optical disks, photomasks, and other substrates.
Such a substrate processing apparatus typically applies a plurality of successive processing to a single substrate. The substrate processing apparatus as described in JP 2003-324139 A comprises an indexer block, an anti-reflection film processing block, a resist film processing block, a development processing block, and an interface block. An exposure device is arranged adjacent to the interface block as an external device separate from the substrate processing apparatus.
In the above-described substrate processing apparatus, a substrate is carried from the indexer block into the anti-reflection film processing block and the resist film processing block, where the formation of an anti-reflection film and resist film coating processing are applied to the substrate. The substrate is then carried to the exposure device through the interface block. After exposure processing has been applied to the resist film on the substrate by the exposure device, the substrate is transported to the development processing block through the interface block. In the development processing block, development processing is applied to the resist film on the substrate to form a resist pattern thereon, and the substrate is subsequently carried into the indexer block.
With recent improvements in the density and integration of devices, making finer resist patterns have become very important. Conventional exposure devices typically perform exposure processing by providing reduction projection of a reticle pattern on a substrate through a projection lens. With such conventional exposure devices, however, the line width of an exposure pattern is determined by the wavelength of the light source of an exposure device, thus making it impossible to make a resist pattern finer than that.
For this reason, a liquid immersion method is suggested as a projection exposure method allowing for finer exposure patterns (refer to, e.g., WO99/49504 pamphlet). In the projection exposure device according to the WO99/49504 pamphlet, a liquid is filled between a projection optical system and a substrate, resulting in a shorter wavelength of exposure light on a surface of the substrate. This allows for a finer exposure pattern.
However, in the projection exposure device according to the aforementioned WO99/49504 pamphlet, exposure processing is performed with the substrate and the liquid being in contact with each other. Accordingly, part of the component of a resist applied on the substrate is eluted in the liquid. The resist component eluted in the liquid remains on a surface of the substrate, which may become the cause of a defect.
The resist component eluted in the liquid contaminates the lens of the exposure device. This may cause a defective dimension and a defective shape of the exposure pattern.